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Home >> Toyota >> 1989 >> MR2 4A-GE, Standard, C52 >> Repair and Diagnosis >> Engine Performance >> System >> System/Component Tests - EFI >> Fuel Control >> Deceleration Fuel-Cut System

Deceleration Fuel-Cut System

  1. Connect a tachometer to engine (to monitor needle fluctuations). See ADJUSTMENTS for tachometer attaching points. Start engine and warm to operating temperature. Ensure A/C and other accessories are off.
  2. Unplug throttle position sensor connector from throttle position sensor. Short terminals IDL and E1 (or E2) on wire side of connector. See Fig 1.
  3. Gradually raise engine RPM. Fuel-cut operation can be checked by noting the fluctuation of tachometer needle. Fluctuation indicates fuel-cut system is being turned on and off. See Fig 2. Check that fuel-cut points and fuel return points are within specifications. See DECELERATION FUEL-CUT & FUEL RETURN RPM table.
DECELERATION FUEL-CUT & FUEL RETURN RPM

Model Fuel-Cut Engine RPM Fuel Return Engine RPM
A/C Off 1600 1200
A/C On 1900 1500
Fig 1: Terminal Connector For Testing Deceleration Fuel-Cut RPM
G95433Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002
Fig 2: Needle Fluctuations When Testing Fuel-Cut RPM
G95438Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002